The present invention relates to an apparatus for testing and filling a cooling system of a motor vehicle with coolant.
Periodically, it is necessary to replace the coolant in the cooling system for a motor vehicle engine. For this purpose, a stopcock has been provided at the bottom of the radiator. In order to drain the system, the stopcock is opened and a cap at the top of the radiator is removed to allow air to enter the system braking a vacuum which would otherwise prevent the flow of old spent coolant through the stopcock. On some newer vehicles, there is no radiator cap on the radiator and a remote overflow recovery tank or reservoir must be opened to access the cooling system.
Years ago a service technician draining the radiator simply allowed the spent coolant to flow to a floor drain in the garage from which it entered the municipal sewer system. With increased concerns about harming the environment, such dumping of coolant chemicals, which often contain heavy metals, into a sewer system has been prohibited. Now the service technician must place a pan beneath the stopcock in which to catch the coolant draining from the engine. The technician must then pour the coolant into a suitable container for proper disposal according to environmental protection regulations. The recovered coolant alternatively may be delivered to a recycling center which removes the contaminants and sells the cleansed coolant.
After the spent coolant is removed from the motor vehicle, the cooling system has to be filled with new coolant. This is accomplished by closing the stopcock and pouring the new coolant into the filler neck at the top of the engine that was opened by removal of the radiator cap. In the newer vehicles without a radiator cap, refilling is done through the remote overflow recovery tank or reservoir. When the mechanic is working on the cooling system, often the drained coolant is placed back into the system, if the coolant is relatively fresh and uncontaminated.
Simply pouring the coolant into the filler opening is relatively time consuming and prone to coolant being spilled onto the floor of the garage. In addition, this process may not completely fill the cooling system with new coolant, as air which entered during the draining stage becomes entrapped within cavities in upper sections of the engine during refilling. Therefore, the engine often has to be operated for a period of time to flush the air into the upper part of the radiator from which the air can be replaced later with more coolant added to the system. Many new vehicles manufacturers have recognized this entrapped air as a significant problem. In response, they have manufactured and inserted bleed valves at various locations to assist the technician in ridding the unwanted, entrapped air. There have also been various model specific procedures and guidelines developed to assist the technician but few additional advantages have been realized and it is still a very time consuming operation for the service technicians.
The present invention provides an apparatus for rapidly filling a motor vehicle cooling system with coolant.
That apparatus includes a service cap for attachment to the filler neck of the radiator. The service cap comprises a body, a collar, a resilient sleeve and a compression tube. The body has a passage there through and has external threads on an exterior surface. The collar is threaded onto the external threads of the body and has a first aperture. The resilient sleeve abuts the collar and has a second aperture. A head at one end of the compression tube abuts the sleeve with the compression tube extending through the first and second apertures. Another end of the compression tube is secured in the passage of the body. Movement of the collar on the threads of the body draws the compression tube through the collar and compresses the sleeve against the collar. This action produces outward expansion of the sleeve which seals the cap to the inside of the radiator filler neck.
In the preferred embodiment of the present invention, a valve is connected to the passage in the body to control flow of air and coolant through the passage. A pressure gauge also can be connected to the passage in the body.
The present cap is used to evacuate air from the cooling system by a vacuum source connected to the valve. The vacuum source can constitute a venturi assembly with a suction port connected to the valve, a fluid inlet and a fluid outlet. A muffler may be connected to the fluid outlet. After the evacuation of air, a source of coolant is connected to the valve with the coolant being drawn into the cooling system by the previously created vacuum.
In another embodiment, the collar is incorporated into the body and a resilient rubber cone that will accommodate various sizes of openings replaces the tubular rubber sleeve. Instead of expanding to seal on the inner opening of the radiator, the cone can be held in place or just sit there. The vacuum generated in the cooling system will hold the seal in place and allow quicker connection and reuse in a variety of different openings.
In another embodiment, a traverse aperture extends from one side across the body to the opposite side, thereby providing a connection so that the vacuum source is always connected to the apparatus. Thus, a coupler and a male coupling are not required.
In yet another embodiment, the valve and coupling are combined into one assembly, a self-closing coupler is used that closes when disengaged and opens when engaged.